In Robert’s tide clock, an Arduino programmed with the tide prediction library for Anchorage Alaska keeps time with a real time clock (RTC) chip. At set intervals, the Arduino checks the current time, and makes a … Continue Reading

Joe Thorley at Poisson Consulting has released a new R package, rtide, (on which I am listed as a co-author) that provides the ability to predict future (and past) tide heights for 637 different tide stations in the United States and associated territories. The underlying data, consisting of tide harmonic constituents, are collected and released by the National Oceanic and Atmospheric Administration. The author of the definitive open source tide prediction software, XTide, collates those harmonic data into a usable format, and we have harvested the data to create the … Continue Reading

I recently dredged up an old poster on tide heights and tidal datums that several of us put together back in graduate school and presented at the Western Society of Naturalists meeting in either 2003 or 2004. This was a hot topic (for 5 or so people) at the time, since the national tidal datums for the United States had all just been updated.

Myself and Jeremy Long recently had a paper published in PeerJ (open access, free to read) describing the use of an Arduino microcontroller to predict tides and regulate the water levels in aquaria in synchrony with the natural tides. You can read more about that tide controller system here and further variations here.

As part of the process of putting a poster together on the Tide Height Controller project for a meeting of the Western Society of Naturalists, I whipped up a simple little 3-piece tide clock that shows a live display of the tide for … Continue Reading

Edit: There is now a full-fledged R package, rtide, to accomplish the same basic task of generating time series of tide predictions that is outlined here. See this more recent post for information.

In the previous post I outlined how to query the XTide software with R and parse the results into a handy-dandy data frame. The biggest hurdle with that method is getting XTide up and running on your computer. The code outlined here works entirely within R, so you don’t need XTide installed on your computer. The trade-off is that it provides substantially … Continue Reading

Edit: There is now a full-fledged R package, rtide, to accomplish the same basic task of generating time series of tide predictions that is outlined here. See this more recent post for information.

XTide is an open-source program that predicts tide heights and current speeds for hundreds of tide and current stations around the United States. It can be used to produce tide predictions in the past and future for a site at your chosen interval (down to the minute), as well as producing sunrise and sunset times, moon phases, and times when the tide level … Continue Reading

In the previous post, I outlined some Arduino code to generate tide height predictions for a NOAA tidal reference station.

Now let’s do something useful with this newfound functionality. In the experiments I run, it’s useful to keep intertidal animals like snails and limpets on a natural tidal cycle. In addition, some animals like high-shore limpets really dislike being continuously submerged, and will crawl up out of the tank and die when they dry out. In this case, I built a “limpet splasher” system that sprays water in the aquarium for a few seconds at a time with pauses in … Continue Reading

A collaborator of mine, Dr. Jeremy Long at SDSU, approached me with the idea of building a system to recreate rising and falling tide heights in his aquaria. One of the keys to making this work was having some way to specify what the tide height should be at any given time. While there is no shortage of websites and software that will give you tide predictions, they generally require an internet connection or a full-fledged computer to run tide prediction software, neither of which were necessarily desirable solutions when we wanted to control tides in aquaria that … Continue Reading